The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
In the prior art, a buck IC sets an output voltage by using a feedback resistor. When a feedback voltage is less than a reference voltage, a constant-on-time (COT) control circuit outputs a gate pulse, so that setting of the output voltage can be implemented. The feedback voltage pulls back a comparator inside the IC, and is compared with a reference voltage inside the IC. When the feedback voltage is less than the reference voltage, the gate pulse generates a group of signals and provides the group of signals to a power stage for a voltage boost, so as to achieve an effect of voltage balance. A biggest advantage of such a voltage feedback control manner is that when an output current is rapidly switched between light load and heavy load, a switching frequency of a switch of the IC is changed, so as to achieve an effect of low ripples. However, when two COT buck ICs are excessively close in the layout and wiring, a feedback voltage of one COT buck IC may be interfered with when the other COT buck IC outputs a gate pulse, causing the feedback voltage to be less than a reference voltage to lead to an error, resulting in that ripples of an output voltage become large.